According to the different cut-offs used to define G6PDd and using the
quantitative G6PD assay as the gold standard, classical diagnostic test
performance measures were determined: Sensitivity (Se), Specificity (Sp),
Deficient/Positive Predictive Value (PPV) and Normal/Negative Predictive Value
(NPV) [28]. Test performances of PoCs were also compared between samples
collected from capillary/venous blood, and from capillary/white cell depleted
venous blood.
The mean, median, standard deviation and ranges were determined for all
G6PD enzyme activity values by gender and type of blood sample (capillary,
venous, white cell depleted venous). The ANOVA test, the Mann-Whitney U test
and the Student’s t test were used for comparisons of continuous variables. For
categorical variables, Chi-squared or Fisher’s exact tests were used to assess
significant differences in proportions. Odds ratios were used to compare the
relative odds of the occurrence of G6PDd, given exposure to the variable of
interest [29]. Comparisons showing p-value , 0.05 was considered to be
statistically significant.